Get the 'nearest' CSS color names to a given hex RGB color value

css_color.py

#!/usr/bin/env python

from operator import itemgetter
import sys
import json
import math
import re

# usage: ./color.py [hex RGB color]
# returns the five 'closest' CSS color names to the input color

# below lifted gleefully from https://github.com/bahamas10/css-color-names/blob/master/css-color-names.json

data_json = """
{
  "aliceblue": "#f0f8ff",
  "antiquewhite": "#faebd7",
  "aqua": "#00ffff",
  "aquamarine": "#7fffd4",
  "azure": "#f0ffff",
  "beige": "#f5f5dc",
  "bisque": "#ffe4c4",
  "black": "#000000",
  "blanchedalmond": "#ffebcd",
  "blue": "#0000ff",
  "blueviolet": "#8a2be2",
  "brown": "#a52a2a",
  "burlywood": "#deb887",
  "cadetblue": "#5f9ea0",
  "chartreuse": "#7fff00",
  "chocolate": "#d2691e",
  "coral": "#ff7f50",
  "cornflowerblue": "#6495ed",
  "cornsilk": "#fff8dc",
  "crimson": "#dc143c",
  "cyan": "#00ffff",
  "darkblue": "#00008b",
  "darkcyan": "#008b8b",
  "darkgoldenrod": "#b8860b",
  "darkgray": "#a9a9a9",
  "darkgreen": "#006400",
  "darkgrey": "#a9a9a9",
  "darkkhaki": "#bdb76b",
  "darkmagenta": "#8b008b",
  "darkolivegreen": "#556b2f",
  "darkorange": "#ff8c00",
  "darkorchid": "#9932cc",
  "darkred": "#8b0000",
  "darksalmon": "#e9967a",
  "darkseagreen": "#8fbc8f",
  "darkslateblue": "#483d8b",
  "darkslategray": "#2f4f4f",
  "darkslategrey": "#2f4f4f",
  "darkturquoise": "#00ced1",
  "darkviolet": "#9400d3",
  "deeppink": "#ff1493",
  "deepskyblue": "#00bfff",
  "dimgray": "#696969",
  "dimgrey": "#696969",
  "dodgerblue": "#1e90ff",
  "firebrick": "#b22222",
  "floralwhite": "#fffaf0",
  "forestgreen": "#228b22",
  "fuchsia": "#ff00ff",
  "gainsboro": "#dcdcdc",
  "ghostwhite": "#f8f8ff",
  "goldenrod": "#daa520",
  "gold": "#ffd700",
  "gray": "#808080",
  "green": "#008000",
  "greenyellow": "#adff2f",
  "grey": "#808080",
  "honeydew": "#f0fff0",
  "hotpink": "#ff69b4",
  "indianred": "#cd5c5c",
  "indigo": "#4b0082",
  "ivory": "#fffff0",
  "khaki": "#f0e68c",
  "lavenderblush": "#fff0f5",
  "lavender": "#e6e6fa",
  "lawngreen": "#7cfc00",
  "lemonchiffon": "#fffacd",
  "lightblue": "#add8e6",
  "lightcoral": "#f08080",
  "lightcyan": "#e0ffff",
  "lightgoldenrodyellow": "#fafad2",
  "lightgray": "#d3d3d3",
  "lightgreen": "#90ee90",
  "lightgrey": "#d3d3d3",
  "lightpink": "#ffb6c1",
  "lightsalmon": "#ffa07a",
  "lightseagreen": "#20b2aa",
  "lightskyblue": "#87cefa",
  "lightslategray": "#778899",
  "lightslategrey": "#778899",
  "lightsteelblue": "#b0c4de",
  "lightyellow": "#ffffe0",
  "lime": "#00ff00",
  "limegreen": "#32cd32",
  "linen": "#faf0e6",
  "magenta": "#ff00ff",
  "maroon": "#800000",
  "mediumaquamarine": "#66cdaa",
  "mediumblue": "#0000cd",
  "mediumorchid": "#ba55d3",
  "mediumpurple": "#9370db",
  "mediumseagreen": "#3cb371",
  "mediumslateblue": "#7b68ee",
  "mediumspringgreen": "#00fa9a",
  "mediumturquoise": "#48d1cc",
  "mediumvioletred": "#c71585",
  "midnightblue": "#191970",
  "mintcream": "#f5fffa",
  "mistyrose": "#ffe4e1",
  "moccasin": "#ffe4b5",
  "navajowhite": "#ffdead",
  "navy": "#000080",
  "oldlace": "#fdf5e6",
  "olive": "#808000",
  "olivedrab": "#6b8e23",
  "orange": "#ffa500",
  "orangered": "#ff4500",
  "orchid": "#da70d6",
  "palegoldenrod": "#eee8aa",
  "palegreen": "#98fb98",
  "paleturquoise": "#afeeee",
  "palevioletred": "#db7093",
  "papayawhip": "#ffefd5",
  "peachpuff": "#ffdab9",
  "peru": "#cd853f",
  "pink": "#ffc0cb",
  "plum": "#dda0dd",
  "powderblue": "#b0e0e6",
  "purple": "#800080",
  "rebeccapurple": "#663399",
  "red": "#ff0000",
  "rosybrown": "#bc8f8f",
  "royalblue": "#4169e1",
  "saddlebrown": "#8b4513",
  "salmon": "#fa8072",
  "sandybrown": "#f4a460",
  "seagreen": "#2e8b57",
  "seashell": "#fff5ee",
  "sienna": "#a0522d",
  "silver": "#c0c0c0",
  "skyblue": "#87ceeb",
  "slateblue": "#6a5acd",
  "slategray": "#708090",
  "slategrey": "#708090",
  "snow": "#fffafa",
  "springgreen": "#00ff7f",
  "steelblue": "#4682b4",
  "tan": "#d2b48c",
  "teal": "#008080",
  "thistle": "#d8bfd8",
  "tomato": "#ff6347",
  "turquoise": "#40e0d0",
  "violet": "#ee82ee",
  "wheat": "#f5deb3",
  "white": "#ffffff",
  "whitesmoke": "#f5f5f5",
  "yellow": "#ffff00",
  "yellowgreen": "#9acd32"
}"""

data = json.loads(data_json)
hexext = re.compile('#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})')

def colorspace_point(hexcol):
    m = hexext.search(hexcol)
    if m:
        return [int(a, 16) for a in m.groups()]

def distance(c1, c2):
    col1 = isinstance(c1, str) and colorspace_point(c1) or c1
    col2 = isinstance(c2, str) and colorspace_point(c2) or c2
    return math.sqrt( sum([(col1[a]-col2[a])**2 for a in (0,1,2)]) )

def compile(data):
    return {k: colorspace_point(v) for k, v in data.items()}

def nearest(color, data, n=1):
    ds = [ (k, v, distance(color, v)) for k, v in data.items() ]
    return sorted(ds, key=itemgetter(2))[:n]
    
if __name__ == '__main__':
    cd = compile(data)
    c = sys.argv[1]
    for v in (nearest(c, cd, 5)):
        print(v)